FIELD OF THE INVENTION
This invention directs itself to audit monitoring systems for use with coin operated vending machines. In particular, this invention directs itself to an audit monitoring system having an interface assembly for retrofit coupling with existing vending systems of various types and manufacture. Still further, this invention directs itself to an audit monitoring system having a microprocessor controlled audit monitoring assembly coupled to an interface assembly, both being installed in an existing coin operated vending system for monitoring control signals between the vending machine's controller and its funds receiving and dispensing equipment. More in particular, this invention pertains to a microprocessor controlled audit monitoring system wherein predetermined parameters utilized for interpreting transaction data for the coin operated vending machine is output from the system's memory responsive to an identification code input thereto. Further, this invention directs itself to an audit monitoring system utilizing a clock/counter implemented within the microprocessor for such functions as timing power failures and door openings. Still further, this invention is directed to an audit monitoring system which monitors the vending machine's motor matrix in order to identify the occurrence of a vend and the location of the vended product. Additionally, the audit monitoring system of this invention interfaces with the vending machine's motor matrix by monitoring the control signals which are communicated between the vending machine's controller and the motor matrix and interpreting those signals to identify the matrix location of the motor being driven to vend a selected product.